Monday marked the biggest showdown in recent weeks between Israel's military and Gaza's Hamas rulers along the volatile border.

GAZA CITY, Gaza Strip (AP) — Thousands of Palestinian protesters gathered along the border with Israel on Monday, drawing Israeli live fire in a bloody showdown that threatened to cast a shadow over Israel's festive inauguration of the new U.S. Embassy in contested Jerusalem.

Protesters set tires on fire, sending thick plumes of black smoke into the air at several spots along the border, while the Israeli military said protesters assaulted the border fence. At least seven Palestinians were killed while over 500 were wounded by Israeli live fire, according to Palestinian health officials.

In the West Bank, several thousand people gathered in the center of Ramallah, while hundreds marched to the Qalandiya crossing on the outskirts of Jerusalem, where protesters threw stones at Israeli troops.

The protest in Gaza was to be the biggest yet in a weekslong campaign against a decade-old blockade of the territory. The march was also directed at the inauguration of the U.S. Embassy in Jerusalem later Monday. The relocation of the embassy from Tel Aviv has infuriated the Palestinians, who seek east Jerusalem as a future capital.

Monday marked the biggest showdown in recent weeks between Israel's military and Gaza's Hamas rulers along the volatile border.

It is the culmination of a campaign, led by the Islamic militant Hamas and fueled by despair among Gaza's 2 million people, to break the decade-old border blockade of the territory by Israel and Egypt. Since weekly border marches began in late March, 49 Palestinian protesters have been killed and more than 2,300 wounded by Israeli army fire.

Hamas leaders have suggested a border breach is possible Monday, while Israel has warned it would prevent protesters from breaking through the barrier at any cost.

Lt. Col. Jonathan Conricus, an Israeli military spokesman, said the army had bolstered its front-line forces along the border, but also set up additional "layers" of security in and around neighboring communities to defend Israeli civilians in case of a mass breach. He said there already had been several "significant attempts" to break through the fence.

"Even if the fence is breached, we will be able to protect Israeli civilians from attempts to massacre or kidnap or kill them," he said.

With Israel and Hamas digging in, there is growing concern about large numbers of casualties. The timing of Monday's events was deeply symbolic, both to Israel and the Palestinians.

The U.S. said it chose the date to coincide with the 70th anniversary of Israel's establishment.

But it also marks the anniversary of what Palestinians call their "nakba," or catastrophe, a reference to the uprooting of hundreds of thousands who fled or were expelled from what is now Israel during the 1948 war surrounding Israel's independence.

A majority of Gaza's 2 million people are descendants of refugees, and the protests have been billed as the "Great March of Return" to long-lost homes in what is now Israel.

In one of the border areas east of Gaza City, Mohammed Hamami, a 40-year-old civil servant, joined a crowd of hundreds of protesters, along with his mother and five children.

"Today we are here to send a message to Israel and its allies that we will never give up on our land," he said.

"We will cross the border and impose new realities like the reality Trump imposed in Jerusalem," he added, referring to President Donald Trump's decision in December to recognize Jerusalem as Israel's capital and then move the U.S. Embassy there.

Some protesters moved to within about 150 meters (yards) of the border fence. A reporter saw two men who tried to advance further being shot in the legs by Israeli troops.

Clouds of black smoke from burning tires rose into the air. Earlier Monday, Israeli drones dropping incendiary material had pre-emptively set ablaze some of the tires collected in advance by activists.

Protesters have used the thick smoke as cover against Israeli snipers perched on high sand berms on the other side of the border. The army accuses Hamas of using the protests as cover to plan or carry out attacks.

Leaflets dropped over Gaza by army jets warned that those approaching the border "jeopardize" their lives. The warning said the army is "prepared to face all scenarios and will act against every attempt to damage the security fence or harm IDF soldiers or Israeli civilians."

In Jerusalem, top Trump administration officials attended events linked to the inauguration of the embassy later Monday.

Treasury Secretary Steven Mnuchin said that it was a U.S. "national security priority" to move the embassy from Tel Aviv to Jerusalem.

Trump's decision to go forward with a campaign promise to move the American embassy from Tel Aviv to Jerusalem was welcomed by Israel and condemned by the Palestinians. Previous presidents had signed a waiver postponing the move, citing national security.

Israel captured east Jerusalem in the 1967 Mideast war and annexed it in a move not recognized by the international community. The Palestinians seek the city's eastern half as the capital of a future state.

Palestinian President Mahmoud Abbas cut ties with the Trump administration and declared it unfit to remain in its role as the sole mediator in peace talks.

Saeb Erekat, a senior Abbas aide, blasted the Trump administration Monday, saying Trump had violated a promise to hold off on moving the embassy to give peace talks a chance and that his administration is "based on lies."

Erekat said the Trump administration has "become part of the problem, not part of the solution."

Administration officials have dismissed Palestinian criticism, portraying the embassy opening as an essential step toward an eventual Israeli-Palestinian peace deal. However, they have not said how they will move forward without the Palestinians.

Israeli Prime Minister Benjamin Netanyahu praised Trump's "bold decision" in upending decades of U.S. policy by recognizing Jerusalem as Israel's capital. "It's the right thing to do," a smiling Netanyahu told the jubilant crowd at a reception in Jerusalem late Sunday.

Although Trump has said his declaration does not set the final borders of the city, his recognition of Jerusalem as Israel's capital has been perceived by both Israel and the Palestinians as taking Israel's side in the most sensitive issue in their conflict.

Only two countries, Guatemala and Paraguay, have said they will follow suit. Most of the world maintains embassies in Tel Aviv, saying the Jerusalem issue must first be resolved.

In a reflection of the deep sensitivities, dozens of countries — including Britain, France and Germany — skipped a celebration Sunday night at the Israeli Foreign Ministry.

Monday's opening will be attended by Trump's daughter Ivanka and son-in-law Jared Kushner, who both serve as White House advisers. Kushner leads the Trump Mideast team.__Ben Zion reported from Jerusalem. Associated Press writers Mohammed Daraghmeh in Ramallah, West Bank, and Karin Laub in Amman, Jordan contributed to this report.